 
         ;; 1. generate sentence in target language.
         ;; resolve future
-        target-language-sentence (engine/generate spec target-language-model :enrich true)
-        
+        target-language-sentence (engine/generate spec target-language-model
+                                                  :enrich true
+                                                  :truncate-children false)
+        ;; we don't want to truncate because we want to store the entire tree in the _structure_ and _serialized_ columns of the database,
+        ;; so that we can search for them with specifications that might include :comp and :head search keys.
+        ;; for example, (defn fill-language-by-spec) is passed a _spec_ param which, depending on the language's
+        ;; writer implementation (e.g. babel.italiano/writer searches based on :comp and :head).
         target-language-sentence (if (:morph-walk-tree target-language-model)
                                    (merge ((:morph-walk-tree target-language-model) target-language-sentence)
                                           target-language-sentence)

        json-spec (json/write-str spec)
        current-count
        (:count
         (first
          (exec-raw ["SELECT count(*) FROM expression 
                         WHERE structure @> ?::jsonb
                           AND language=?"
                       [(json/write-str spec) language]]
                      :results)))]
    (log/debug (str "current-count for spec: " spec "=" current-count))

                                           (map (fn [number]
                                                  (let [spec (unify spec
                                                                    {:comp {:synsem {:agr {:number number}}}})]
                                                    (log/debug (str "generating from spec: " spec "; input-spec was:" input-spec))
                                                    (try
                                                      (process [{:fill-one-language
                                                                 {:count 1
